#include <bits/stdc++.h>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector < int >  mu[100001];
int n,m;
int v[100001];



void dfs(int nod)
{
    v[nod]=1;
    for(int j=0;j<mu[nod].size();j++)
    {
      /// cout<<mu[nod][j]<<" ";
      if(!v[mu[nod][j]])
      dfs(mu[nod][j]);
    }
   /// cout<<endl;
}

int main()
{
    fin>>n>>m;

   for(int i=1;i<=m;i++)
   {
       int x,y;
       fin>>x>>y;
       mu[x].push_back(y);
       mu[y].push_back(x);
   }
int nr=0;

     for(int i=1;i<=n;i++)
         if(!v[i])
            {dfs(i);nr++;}
        fout<<nr;

    return 0;
}